thakis added a subscriber: thakis. ================ Comment at: lib/Driver/Tools.cpp:398 @@ +397,3 @@ + FoundPTH = !UsePCH; + } + } ---------------- kimgr wrote: > kimgr wrote: > > kimgr wrote: > > > kimgr wrote: > > > > Add a `break;` here so we don't continue searching after a valid path > > > > has been found > > > The GCC docs here [1] say: > > > > > > If not found there, it is searched for in the remainder of the > > > #include "..." search chain as normal. > > > > > > I can't tell if the quotes are significant and if they mean only -I is > > > searched. I don't have a GCC environment currently to test with. > > > > > > [1] > > > https://gcc.gnu.org/onlinedocs/gcc-4.9.3/gcc/Preprocessor-Options.html#index-nostdinc_002b_002b-1026 > > I found a FreeBSD machine and set up GCC. I had to adjust the repro case to > > use `truss` instead of `strace`, so I hope I didn't mess anything up. > > > > I removed the rule generating the .gch file, so GCC would have to keep > > searching and it appears to be following the entire include search path, > > including system paths. Trace below: > > > > ... > > 30860: stat("./precompiled.header.gch",0x7fffffffe540) ERR#2 'No such file > > or directory' > > 30860: open("./precompiled.header",O_NOCTTY,0666) ERR#2 'No such file or > > directory' > > 30860: stat("./build/include/precompiled.header.gch",0x7fffffffe540) ERR#2 > > 'No such file or directory' > > 30860: open("./build/include/precompiled.header",O_NOCTTY,0666) ERR#2 'No > > such file or directory' > > 30860: stat("./include/precompiled.header.gch",0x7fffffffe540) ERR#2 'No > > such file or directory' > > 30860: open("./include/precompiled.header",O_NOCTTY,0666) ERR#2 'No such > > file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/local",{ mode=drwxr-xr-x ,inode=115,size=16,blksize=4096 > > }) = 0 (0x0) > > 30860: lstat("/usr/local/lib",{ mode=drwxr-xr-x > > ,inode=16476,size=1318,blksize=84480 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48",{ mode=drwxr-xr-x > > ,inode=24335,size=66,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include",{ mode=drwxr-xr-x > > ,inode=24336,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include/c++",{ mode=drwxr-xr-x > > ,inode=24337,size=98,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/include/c++/precompiled.header",0x7fffffffd3d8) > > ERR#2 'No such file or directory' > > 30860: > > stat("/usr/local/lib/gcc48/include/c++/precompiled.header.gch",0x7fffffffe540) > > ERR#2 'No such file or directory' > > 30860: > > open("/usr/local/lib/gcc48/include/c++/precompiled.header",O_NOCTTY,0666) > > ERR#2 'No such file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/local",{ mode=drwxr-xr-x ,inode=115,size=16,blksize=4096 > > }) = 0 (0x0) > > 30860: lstat("/usr/local/lib",{ mode=drwxr-xr-x > > ,inode=16476,size=1318,blksize=84480 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48",{ mode=drwxr-xr-x > > ,inode=24335,size=66,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include",{ mode=drwxr-xr-x > > ,inode=24336,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include/c++",{ mode=drwxr-xr-x > > ,inode=24337,size=98,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/include/c++/x86_64-portbld-freebsd10.1",{ > > mode=drwxr-xr-x ,inode=21305,size=4,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/include/c++/x86_64-portbld-freebsd10.1/precompiled.header",0x7fffffffd3d8) > > ERR#2 'No such file or directory' > > 30860: > > stat("/usr/local/lib/gcc48/include/c++//x86_64-portbld-freebsd10.1/precompiled.header.gch",0x7fffffffe540) > > ERR#2 'No such file or directory' > > 30860: > > open("/usr/local/lib/gcc48/include/c++//x86_64-portbld-freebsd10.1/precompiled.header",O_NOCTTY,0666) > > ERR#2 'No such file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/local",{ mode=drwxr-xr-x ,inode=115,size=16,blksize=4096 > > }) = 0 (0x0) > > 30860: lstat("/usr/local/lib",{ mode=drwxr-xr-x > > ,inode=16476,size=1318,blksize=84480 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48",{ mode=drwxr-xr-x > > ,inode=24335,size=66,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include",{ mode=drwxr-xr-x > > ,inode=24336,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include/c++",{ mode=drwxr-xr-x > > ,inode=24337,size=98,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/include/c++/backward",{ mode=drwxr-xr-x > > ,inode=21290,size=10,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/include/c++/backward/precompiled.header",0x7fffffffd3d8) > > ERR#2 'No such file or directory' > > 30860: > > stat("/usr/local/lib/gcc48/include/c++//backward/precompiled.header.gch",0x7fffffffe540) > > ERR#2 'No such file or directory' > > 30860: > > open("/usr/local/lib/gcc48/include/c++//backward/precompiled.header",O_NOCTTY,0666) > > ERR#2 'No such file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/local",{ mode=drwxr-xr-x ,inode=115,size=16,blksize=4096 > > }) = 0 (0x0) > > 30860: lstat("/usr/local/lib",{ mode=drwxr-xr-x > > ,inode=16476,size=1318,blksize=84480 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48",{ mode=drwxr-xr-x > > ,inode=24335,size=66,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/gcc",{ mode=drwxr-xr-x > > ,inode=145103,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1",{ > > mode=drwxr-xr-x ,inode=145104,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4",{ > > mode=drwxr-xr-x ,inode=145105,size=16,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include",{ > > mode=drwxr-xr-x ,inode=145106,size=64,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include/precompiled.header",0x7fffffffd3d8) > > ERR#2 'No such file or directory' > > 30860: > > stat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include/precompiled.header.gch",0x7fffffffe540) > > ERR#2 'No such file or directory' > > 30860: > > open("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include/precompiled.header",O_NOCTTY,0666) > > ERR#2 'No such file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/local",{ mode=drwxr-xr-x ,inode=115,size=16,blksize=4096 > > }) = 0 (0x0) > > 30860: lstat("/usr/local/include",{ mode=drwxr-xr-x > > ,inode=16474,size=218,blksize=14336 }) = 0 (0x0) > > 30860: lstat("/usr/local/include/precompiled.header",0x7fffffffd3d8) ERR#2 > > 'No such file or directory' > > 30860: stat("/usr/local/include/precompiled.header.gch",0x7fffffffe540) > > ERR#2 'No such file or directory' > > 30860: open("/usr/local/include/precompiled.header",O_NOCTTY,0666) ERR#2 > > 'No such file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/local",{ mode=drwxr-xr-x ,inode=115,size=16,blksize=4096 > > }) = 0 (0x0) > > 30860: lstat("/usr/local/lib",{ mode=drwxr-xr-x > > ,inode=16476,size=1318,blksize=84480 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48",{ mode=drwxr-xr-x > > ,inode=24335,size=66,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/gcc",{ mode=drwxr-xr-x > > ,inode=145103,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1",{ > > mode=drwxr-xr-x ,inode=145104,size=3,blksize=131072 }) = 0 (0x0) > > 30860: lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4",{ > > mode=drwxr-xr-x ,inode=145105,size=16,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include-fixed",{ > > mode=drwxr-xr-x ,inode=145194,size=12,blksize=131072 }) = 0 (0x0) > > 30860: > > lstat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include-fixed/precompiled.header",0x7fffffffd3d8) > > ERR#2 'No such file or directory' > > 30860: > > stat("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include-fixed/precompiled.header.gch",0x7fffffffe540) > > ERR#2 'No such file or directory' > > 30860: > > open("/usr/local/lib/gcc48/gcc/x86_64-portbld-freebsd10.1/4.8.4/include-fixed/precompiled.header",O_NOCTTY,0666) > > ERR#2 'No such file or directory' > > 30860: lstat("/usr",{ mode=drwxr-xr-x ,inode=9,size=16,blksize=4096 }) = 0 > > (0x0) > > 30860: lstat("/usr/include",{ mode=drwxr-xr-x > > ,inode=111,size=307,blksize=19968 }) = 0 (0x0) > > 30860: lstat("/usr/include/precompiled.header",0x7fffffffd3d8) ERR#2 'No > > such file or directory' > > 30860: stat("/usr/include/precompiled.header.gch",0x7fffffffe540) ERR#2 'No > > such file or directory' > > 30860: open("/usr/include/precompiled.header",O_NOCTTY,0666) ERR#2 'No such > > file or directory' > > 30860: stat("/usr/share/nls/C/libc.cat",0x7fffffffdf18) ERR#2 'No such file > > or directory' > > 30860: stat("/usr/share/nls/libc/C",0x7fffffffdf18) ERR#2 'No such file or > > directory' > > 30860: stat("/usr/local/share/nls/C/libc.cat",0x7fffffffdf18) ERR#2 'No > > such file or directory' > > 30860: stat("/usr/local/share/nls/libc/C",0x7fffffffdf18) ERR#2 'No such > > file or directory' > > 30860: write(2,"cc1plus: fatal error: precompile"...,68) = 68 (0x44) > > 30860: write(2,"compilation terminated.\n",24) = 24 (0x18) > > ... > > > So it seems that GCC *does* scan the entire header search path. > Unfortunately, that information doesn't seem to be available to the driver > (looks to be set up in CompilerInstance::createPreprocessor. > > Should this logic for PCH/PTH scanning move out of the driver and into the > frontend? gcc also checks if the gch file is a directory and if so finds the first file with matching language / defines etc. It also uses gch files for #included files instead of just -included files (https://gcc.gnu.org/onlinedocs/gcc/Precompiled-Headers.html). I thought clang intentionally did none of this so it doesn't have to stat all these directories.
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